> The fly in the ointment is that the AL-1500 tank L gets mucho hot with
> one 8877. With two tubes and 2x the I-anode, figure c. 4-times as much
> tank loss.
You will need a minimum of 1/4 inch tubing for 20 through 10 meters, and at
LEAST
#12 wire for 160-80-40 meters. The coil form should not be any kind of
plastic, as
it will melt. Even the old robust B&W 800 series tank coil assemblies
experience plastic
coil spacer failure at powers above 3 kw or so. Duplicating the Alpha
77SX/DX tank is
not a good idea either, as it was designed for a plate load of 2100 ohms or
so. Your
plate load with 2 X 8877's will be half that with 4 kv on the anodes. If
chassis space
allows, I use a Multronics or Henry roller coil along with a 1/4 inch
copper tubing coil
for 10 meters.
(((73)))
Phil, K5PC
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